Adjustable releasing tap holder



y 27, 1943 H Q M JAMPOLER 2,325,184:

ADJUSTABLE RELEASING TAP HOLDER Filed Feb. 9, 1942 2 Sheets-Sheet 1 July 27, 1943. H. o. M. JAMPQLER ADJUSTABLE RELEASING TAP HOLDER Filed Feb. 9, 1942 2 sheets-sheet 2 #5675557' OJ. JAN/DOL EAD Patented July 27, 1943 UNITED STATES PATENT OFFICE ADJUSTABLE RELEASING TAP HOLDER Herbert 0. M. Jarnpolerjlfrovidence, R. I. Application February 9, 1942, Serial No. 430,146 3 claims. (ci. 10-134) This invention relates to adjustable releasing tap holders, and has for one of its objects the production of a simple and eiiicient tap holder for use on multiple sipndle drilling and tapping machines, and Which is specially designed to provide high speed tapping and simultaneous tapping of threads of different depth and pitch.

A further object of this invention is the production of an adjustable releasing tap holder wherein a very close tolerance of thread is provided due to the fact that the device is designed s that practically no axial forces exist, while at the same time providingrotating movement and a self-releasing means.

Other objects and advantages of the present invention will appear throughout the following specification and claims.

In the drawings:

Figure 1 is a vertical sectional view of the releasing tap holder, certain parts being shown in elevation;

Figure 2 is a horizontal sectional view taken on line 2-2 of Figure 1;

Figure 3 is a horizontal sectional view taken on line 3 3 of Figure 1;

Figure 4 is a horizontal sectional view taken on line 4--4 of Figure l;

Figure 5 is a perspective view of the driving bushing;

Figure 6 is a perspective view of the tap holder;

Figure '7 is a perspective View of one of the retaining rings;

Figure 8 is an enlarged sectional view of the tap-engaging member releasing means;

Figure 9 is a vertical sectional view of a modified form, certain parts being shown in elevation;

Figure 10 is a horizontal sectional view taken online III-I0 ofFigure 9;

Figure 11 is a horizontal sectional view taken on line I I-I I of Figure 9, and

Figure 12 is a perspective View of the tap holder shown in the form illustrated in Figure 9.

By referring to the drawings, it will be seen that Ill designates the body of the tap holder which is provided with a socket II within which is mounted a driving bushing I2. The body I0 is provided with a channel I3, which channel I3 registers with a channel I4 formed in the outer face of the driving bushing I2. A key I5 of less length than the channels nts in'the channels I3 and I4, to hold the parts against independent rotation and allows the bushing I2 to movc longitudinally of the body II). A bushing supporting ring IB is carried in the lower end of the body I Il and rests upon the split annular expansion ring I 1, which ring I1 lits in the channel I8 formed near the lower end of the body IU. This retaining ring I'I may be replaced, if desired, by any suitable retaining means.

The driving bushing I2 is provided with a central bore I9 into which nts the tap-engaging member 20. The upper end of the tap-engaging member is provided with a square socket 2| for receiving the squared upper end of the tap 22.

The member 20 is provided with a pair of lateral cam lugs 23, which lugs 23 slide vertically within the vertical channels 24 formed in the side walls of the bore I9. The bushing supporting ring I6 is provided with an annular channel 25 in its upper face registering with the lower ends of the vertical channels 24 of the bushing I2. The cam lugs 23 are inclined at their upper ends with the lower portion of the incline 'of less height than the depth of the channel 25 to cause the bushing I2 to be raised and thus disengage the lugs 23. The lugs 23 engage the bottom end of the bushing I2 When thebushing I2 begins to rotate in the opposite direction to withdraw the tap from the previously threaded hole. An expansion coil spring 26 engages a cap plate 2l carried by the upper end of the bushing I2 and the inner end of the socket II to yieldably hold the bushing I2 in contact with the bushing supporting ring I6. A spacing element 28 of a suitable type is carried by the under face of the cap plate 2l to provide a bumper for the upper end of the tap-engaging member 20. Suitable air vents 29 are provided in the upper end of the body I0, as shown in Figure 1. The air vents also serve for the purpose of oiling.

An outer casing 30 is slidably mounted upon the body I0 and is held against independent rotation by means of a tongue 3| fitting in a channel 32 formed in the body I0. The bottom end of the casing 30 is closed by a disc 33, which disc 33 is held inplace by a split annular expansion ring 34 similar to the ring I'I Shown in Figure '7. This ring 34 fits in a suitable channel formed in the lower end of the casing 30, as shown in Figure 1. A light compression coil spring 35 is carried within the casing 30 and engages one end of the casing 30 at one end and the outturned ange 36 at the bottom of the body Ill at its opposite end to normally hold the parts in substantially the position shown in Figure 1.

The tap-engaging member 2U is provided with a shoulder 3'I against which rests'a Washer 38, the washer 38 engaging the disc 33 and normally supporting the tap-engaging member 20. The tap 22 is held within the tap-engaging member 2U by means of a ball 39 which is carried within the aperture 40 formed in the member 20 and of greater diameter than the thickness of the side of the tap-engaging member 2D. The disc 33' is provided with a collar 4I having a. releasing channel 42 into which the ball 39 may partially t for the purpose of releasing the tap 22. A sufficient clearance is provided between the washer 38 and the bottom of the supporting ring I6 to provide for this release. The tap 22 is provided with a slot 22a in the side thereof for receiving the ball 39 as shown in Figures 1 and 4 to prevent the tap 22 from falling out.

The operation of the device is as follows:

'Ihe head of the tooling machine descends down. to the stop and the tap 22 rests in the hole entry. The tap holder or supporting member 20. is pushed down to obtain contact through the medium of the spacing member 28 when downward pressure is provided upon the body Ill.` When the driving spindle or spindles start to rotate the tap 22 will thread into the hole. As the tap 22 moves downwardly into the hole, the disc 33 and casing 3&14

will b e pulled downwardly against the light compression spring 35 with the tap-supporting member 2C, the cam lugs 23 moving downwardly within the channels 24 of the driving bushing I2. When the lugs 23 reach the annular channel 25 of the bushing supporting ring IB, the driving bushing I2 will continue to rotate and the bottom edge of the bushing I2 will ride over the upper inclined faces ofthe lugs 23 and the driving bushing I2 will reciprocate within the body I0, this movement being possible through the medium of the compression spring 26 which allows this bushing I2 to move upwardly of the casing I0. In this way rapid vertical oscillation of the bushing I2 will be provided as the lbushing I2 rotates and rides over the cam lugs 23, the bushing running free and the boring action of the tap 22 being discontinued, the tap 22 remaining stationary. The direction cf rotation may then be reversed by the operator of the machine to withdraw the tap at which time the operation of the parts will be reversed to that above described. When the operation of themachine is reversed, the lugs 23 will again enter the channels 24 andthe lugs 23 will ascend upwardly into the channels 24 withdrawing the tap 22 from the hole which has been threaded in the work.

The thickness of the spacing member 28 determines the depth of the threading and the depth of the threading is equal to the entire distance between the bottom edges of the lugs 23 in the highest position of the tap holder or tapengaging member 20 and the bottom face 42 of the annular channel 25. The highest position may be freely regulated by inserting a spacing member sometimes referred to as a pastil 28 of any required size or height between the tap-supporting member 20 and the plate 21. The height of the spacing member 28 deducted fro-m the maximum available height, which depends upon the size of the entire device, gives the required tapping depth.

The present device, due to the manner of regulation and the manner in which the tap holder is released allows simultaneous threading of the different depth and pitch of thread during the same operation. The head r body I0 of the tapping machine does not move inwardly, but only the casing 30 and the tap-supporting member 20 and the tap.

Where a plurality of taps are used, the movement of the head of the machine is as follows:

First, the head descends vto the lower stop and remains in this position until all the taps reach the bottom and the holders run free. The operator may then reverse the operation to cause the taps to be withdrawn from their respective holes.

,From the foregoing description, it will be seen that a tap holder has been provided which may operate at high speed for threading or tapping holes and by means of the present device simultaneous tapping of threads of different depths and pitch may be provided. Also a very close tolerance of thread may be provided because of the fact that during the operation of 'threading practically no axial force exists but only movement of rotation. Furthermore, a self-releasing device is provided and the head of the drilling or tapping machine remains in a stationary position during the tapping operation, only the casing, the tap supporting member, and the tap moving inwardly with respect to the hole.

In Figures 9 to 12, inclusive, there is shown a modied type of the invention wherein a body is provided having a central bore 5I. A driving bushing 52 is slldably mounted within the body 50 and is held against rotating movement with respect to the body 50 by means of a, key 53. 'I'he driving bushing 52 is supported upon a bushing supporting ring 54, which bushing supporting ring 54 rests upon an expansion washer or ring 55 carried at the lower end of the body 50, this ring 55 being similar to the ring I1 shown in Figure 1. The bushing supporting ring 54 is provided with a channel 56 in its upper face to provide an annular pocket below the bushing 52 for the purpose hereinafter described. A tapengaging member or supporting member 51 is slidably mounted within the bushing 52, and a tap 58 is carried by the member 51, and is secured thereto by means of a transverse pin 59. The tap-engaging or supporting member 51 is provided with a pair of laterally extending cam lugs 60 similar to the lugs 23, and these lugs 60 work within the longitudinally extending channels 6I formed in the inner face of the bushing 52, these channels 6I being similar to the channels 24. A cap plate 62 normally rests upon the upper end of the bushing 52 and a spacing thimble 63 is mounted within the bushing 52 between the cap plate 62 and the inner end of the tapengaging member 51.

The body 50 supports a spring-engaging anchor 64, which is suspended within the upper end of the bore 5I, and this anchor 64 supports the upper end of the tension spring 65 which spring extends down through the thimble 63 and through the cap plate 62 andfis secured to the inner end of the tap-engaging member 51. An expansion coil spring 66 is interposed between the inner end of the bore 5I and the cap plate 62. The body 50 may be provided with suitable vent openings 61 to prevent the tool from being air bound.

The operation of the device of the form shown in Figures 9 to 12 is substantially the same as that previously described, and the member 63 is the equivalent of the member 28. The lugs 60 function in a manner similar to the lugs 23 in order to provide an automatic release. In the form shown in Figure 9, as the tap 58 threads into the work, the tap-engaging member 51 will be pulled downwardly against the tension of the spring 65, and will rotate with the driving bushing 52 until the lugs 60 reach the channel 56, thereby allowing the tap-engaging or supporting member 51 to stop and remain stationary, the bushing 52 having at that time a rapid reciprocating movement against the tension of the spring 66 and top plate 62.

In both forms of the device, the whole vertical movement of the head between the stops is approximately /oo of an inch, which permits the tap to be withdrawn entirely from the threaded hole.

It should be noted that the lugs 23 in conjunction with the channels 24 will provide a ratchet clutch mechanism to automatically release the tap-engaging member and permit the bushing I2 to freely operate while rotating in one direction, but at the Vsame time this structure will permit the tap-engaging member to be withdrawn into the bushing l2 when the direction of rotation of the bushing is reversed. Furthermore, it should be understood that due to the structure of the rings I1 and 34 in Figure 1, and the ring 55 in Figure 9, the parts of the device may be readily disassembled for the purpose of replacement.

Certain detail changes in the mechanical construction may be employed without departing from the spirit of the invention, so long as such changes fall within the scope of the appended claims.

Having described the invention, what is claimed as new is:

l. A device of the class described comprising a body, a driving bushing mounted within said body, the driving bushing having a central bore,

the walls of the bore having longitudinally extending channels, a tap-engaging member mounted within the bore and having lateral lugs movable longitudinally within said channels, a supporting member for said bushing, the supporting member having an annular channel adjacent the bushing and communicating with said channels, the lugs being adapted to be moved into the annular channel when said tap-engaging member reaches a predetermined position with respect to the bushing to permit the driving bushing to freely rotate independently of the tap-engaging member, said lugs having inclined upper faces to permit the driving bushing to rotate freely in one direction, the bushing being slidably mounted within the body and movable in a reciprocating manner as the bushing passes over the lugs, the lugs being adapted to engage the channels when the bushing is operating in the opposite direction for permitting the tapengaging member to automatically move inwardly of the bushing, spring means for normally holding the bushing in contact with the supporting member, a casing for said body, means connecting the casing to said tap-engaging member, and spring means engaging the casing and the body to permit the casing and tapengaging member to move longitudinally of the body and to automatically return the casing to its normal position when the casing and tapengaging member are released.

2. A device of the class described comprising a body, a driving bushing mounted within said body, the driving bushing having a central bore,

the walls of the bore having longitudinally rextending channels, a tap-engaging member tap-engaging member, said lugs having inclined upper faces to permit the driving bushing to rotate freely in one direction, the bushing being slidably mounted within the body and movable in a reciprocating manner as the bushing passes over the lugs, the lugs being adapted to engage the channels when the bushing is operating in .the opposite direction for permitting the tapengaging member to automatically move inwardly of the bushing, spring means for normally holding the bushing in contact with the supporting member, a casing for said body, means connecting the casing to said tap-engaging member, spring means engaging the casing and the vbody to permit the casing and tap-engaging member to move longitudinally of the body and to automatically return the casing to its normal position when the casing and tap-engaging member are released, and means carried by the tap-engaging member for holding a tap `in engagement with the tap-engaging member. f

3. A device of the class described comprising a body, a driving bushing mounted within said body, the driving bushing having'v a central bore, the walls of the bore having `longitudinally extending channels, a tap-engaging member mounted within the bore and having lateral lugs movable longitudinally within said channels, a supporting member for said bushing, the supporting member having an annular channel adjacent the bushing and communicating with said channels, the lugs being adapted to be moved into the annular channel when said tap-engaging member reaches a predetermined position with respect to the bushing to permit the driving .bushing to freely rotate independently ofl the tap-engaging member, said lugs having inclined upper faces to permit the driving bushing to rotate freely in one direction, the bushing being slidably mounted Within the body and movable in a reciprocating manner as the bushing passes over the lugs, the lugs being adapted to engage the channels when the bushing is operating in the opposite direction for permitting the tap- .engaging member to automatically move inwardly of the bushing, spring means for normally holding the bushing in contact with the supporting member, a casing for said body, means connecting the casing to said tap-engaging member, spring means engaging the casing and the body to permit the casing and tap-engaging member to move longitudinally of the body and to automatically return the casing to its normal posi* tion when the casing and tap-engaging member are released, and means for limiting the inward movement of the tap-engaging member within the bushing.

HERBERT O. M. J AMPOLER. 

